“…During the approach process, the tip experiences a surface attractive (negative) force at point A, reaching a maximum attractive force at point B, and encounters repulsive (positive) forces from the substrate. During retraction, the tip overcomes maximum adhesion at point D, returning to zero force at point E . The maximum attractive forces are 58.6 and 12.4 μN for the PIE-40 and PMMA surfaces, respectively.…”